docs: def reset(self):
      """Reset the environment.
  
      Returns:
        Tensor of the current observation.
      """
      observ_dtype = self._parse_dtype(self._env.observation_space)
      observ = tf.py_func(self._env.reset, [], observ_dtype, name='reset')
      observ = tf.check_numerics(observ, 'observ')
      with tf.control_dependencies([
          self._observ.assign(observ),
          self._reward.assign(0),
          self._done.assign(False)]):
        return tf.identity(observ)